Adjustable supporting mechanism for drawing boards



June 23,1925. 1,542,881

A. HOFFMAN ADJUSTABLE SUPPORTING MECHANISM FOR DRAWING BOARDS Filed Nov. 10. 1924 IN V EN T R.

z 13 ATTORNEY positions or angles Patented June 23, 1925.

AD OLPH .HOFFMAN, OF ROCI IESTER, NEW YORK.

j ADJUSTABLE SUPPORTING MncHANrsM FOR DRAWING BOARDS.

Application filed November 10, 1924. Serial No. 748,924. 7

To all whom it may concern: a v i 7 Be it known that I, AnoLrrI HOFFMAN, a citizen of the United States of America,-re-

sidingat Rochester, inthe county of Monroe and State of New York, have invented certain new and useful Adjustable Supporting Mechanism for Drawing Boards, of which the following is a specification. I I

My invention relates to a supporting mechanism for drawing boards, and has for its object to afford a construction by which a board can be readily adjusted to different with reference to the horizontal, and easily clamped in such adjusted position.

"A more particular object of the invention is to provide a simple and practicable ar' range'mentof parts thatcan be manufactured economically, will stand wear, and at the same time insure a positive clamping of the board in such a way that slipping of the board from its adjusted position is not possible after it is once properly clamped;

To these ends, the invention comprises the structure that will appear more clearly from the following description, when read in conjunction with the accompanying drawings, the novel features being pointed out in the claims following the description.

In the drawing:

Figure 1 is a side elevation of a drawing board and supporting stand, including a preferred embodiment of my invention, the board being in upright position;

Figure 2 is an enlarged sidev elevation, with parts broken away, and showing the board in horizontal position;

Figure 3 is an end elevation of the parts illustrated in Figure 2;

Figure 4 is a sectional view on line 4-4 of Figure 3';

Figure 5 is an end elevation of the yoke and post, with the clamping collar and look ing bolt removed;

Figure 6 is an end elevation of the clampin collar, and

igure 7 is a sectional view on line 7-7 of Figure ,6.

Referring more particularly to the drawings, in which like reference numerals throughout the several views indicate the same parts, 1 designates a tripod of conventional form, in which is arranged a vertically adjustable standard 2 upon which is adjustably mounted the drawing Improvements in board 3, and

v. the features' of my invention have to do with the mechanism for clainping'the board in adjusted relation upon. I the standard 2.

To accomplish this, I provide a horizontally disposed sleeve 4 at the upper end of the standard 2, said sleeve affording fixed shoulders at its opposite ends, and 5 is a post that is keyed in said sleeve in any suitable way, as by a'p'in 6 driven through the sleeve and post and held frictionally therein. The post- 5 has its ends protruding be-' yond'the ends of the sleeve 4, to afford bearings for the arms? of a yoke 8, which car-- ries the drawing board 3. Theinner faces of the arms 7 contact with the shoulders formed by the'ends ofthe sleeve 4, the yoke being rotatable on the post 5 for adjustment to differenttangles to the horizontal.

In orderto clamp the yoke in any adjusted position, I employ a clamping collar that isheld against rotation on the post 5v but slidable thereon and adapted to be brought into clamped relation with one. of the arms 7. To this end, I employ a clamping collar 10 which carries a pin 11 engaging an opening or recess 12in the post 5 so as to prevent rotation ofthe collarlO uponthe. post, while permitting its slidable movement thereon.

The clamping collar 10 is forced tightly against the adjacent arm 7 of the yoke, holding the latter clamped between the shoulder at one end of the sleeve 4 and the clamping collar 10. 1 p

A preferable arrangement for accomplishingthis includes a flange 13 at the outer end of the clamping collar 10 and arranged to overlie the end of the post 5, see Figure 4.

A locking member or bolt is provided which comprises a threaded stem 14 engaging a rection to force the clamping collar 10 tightly against the adjacent arm 7 of the yoke which carries the board. This arm of the yoke is held between the shoulder on one end of the sleeve 4 and the clamping collar 10, and since the clamping collar 10,

post 5 and sleeve l are all fixed against any rotative movement, the yoke is tightly secured simply turning the handle 16, and after being once adjusted, there is practically no chance 01 the board supporting yoke coming loose or slipping.

I claim:

1. The combination with a post having a shoulder fixed thereon, of a yoke journalled on the post in engagement with said shoulder, a collar held against rotation on the post and slidable therealong to engagecthe outer face of the yoke, and a locking member having threaded engagement with the post and acting to force the collar and yoke toward said shoulder.

2. The combination with a post, of a sleeve fixedly arranged thereon, a yoke journalled on the post and engaging the ends of the sleeve, a collar held against rotation on the post and slidable therealong to engage one arm of the yoke, and a locking member illtlivr ing threaded engagement with the post and acting to move the collar into clamping engagement with the adjacent arm of the yoke; 3. The combination with a standard including a horizontally arranged sleeve at its upper end, of a post fixed in said. sleeve with its ends protruding therebeyond, a yoke journalled upon said post with arms in engagement with the ends of said sleeve, a collar heldagainst rotation on the post and slidable therealong toward one arm of the yoke, and a locking member having threaded engagement with the post and acting to force the collar into clamping relation with the adjacent arm: of the yoke.

4. In an adjustable supporting mechanism for a drawing board, the combination with a standard having a horizontally disposed sleeve at its upper end, of a post fixed in said sleeve with its ends protruding therebeyond, a board support including a yoke having arms journalled on said post and in engagement with the ends of said sleeve, a collar held against rotation upon the post and slidable thcrealong to engage one of the arms of the yoke, and a locking bolt having threaded engagement with an opening in the end of the: post and acting to force the collar into clamping relation with the adjacent arm of the yoke.

5. In an adjustable supporting mechanism for a drawing board, the combination with a standard having a horizontally disposed sleeve at its upper end and a post fixed in said sleeve with its ends protruding therebeyond, of a board support including a yoke with arms journalledon said post and in engagement with the ends-Iof said sleeve, a clamping collar slidable on one end of said post and carrying a pin which engages a recess in the post to prevent rotation of the collar, said collar including a flange overly,- ing the end ofthe post, and a locking bolt including a threaded stem engaging a threaded opening in the end of the post and a shoulder engaging said flange on the collar and acting to move the latter into c-lamp ing relation with the adjacent arm of the yoke.

In witness, whereof, I have hereunto signed my name.

ADOVLPH HOFFMAN. 

